REDACT: A Systematically Controlled Multilingual Benchmark for Personal Information Detection

Guneesh Vats, Anubha Agrawal, Shikha Singhal, Ajita Dash, Praison Selvaraj, Vidhan Jhawar, Ranga Prasad Chenna, Bharadwaj Y M G


Abstract
Benchmark infrastructure for personally identifiable information (PII) detection remains limited: existing corpora cover few entity types, use ad hoc generation conditions, and do not show which surface conditions cause detector failures. We present REDACT, a systematically controlled multilingual PII benchmark with 13,427 records, 324,078 entity annotations, 51 entity types, 4,127 surface-form patterns, and 25 languages across 9 scripts. A strength-2 covering-array sampler controls nine generation axes: domain, format, difficulty, length, density, code-switching, language, adjacency, and co-occurrence. Three entity-level metadata fields (disclosure status, disclosure form, and a GDPR-aligned sensitivity tier) enable stratified evaluation beyond aggregate or per-type F1. From the full benchmark, we evaluate five detectors (Presidio, GLiNER, the OpenAI Privacy Filter, GPT-4.1, and Claude Sonnet 4.6) on a locked, language-stratified sample of 1,000 records. Aggregate F1 masks an architecture-dependent failure structure: the rule-based detector performs poorly on the policy-sensitive data, including HIGH-sensitivity entity types (recall 0.07) and non-verbatim disclosure forms, while the LLM detectors remain more robust, with the HIGH tier as their strongest sensitivity slice. A three-model reference-free LLM-as-judge assessment corroborates that sensitivity-tier assignment is the task’s hardest axis. We release the benchmark, schema, prompts, and stratified evaluation harness.
Anthology ID:
2026.emnlp-industry.204
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Pepa Atanasova, Gholamreza Haffari, Minghan Wang
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
3426–3440
Language:
URL:
https://aclanthology.org/2026.emnlp-industry.204/
DOI:
Bibkey:
Cite (ACL):
Guneesh Vats, Anubha Agrawal, Shikha Singhal, Ajita Dash, Praison Selvaraj, Vidhan Jhawar, Ranga Prasad Chenna, and Bharadwaj Y M G. 2026. REDACT: A Systematically Controlled Multilingual Benchmark for Personal Information Detection. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track, pages 3426–3440, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
REDACT: A Systematically Controlled Multilingual Benchmark for Personal Information Detection (Vats et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-industry.204.pdf